Roman Army

The Roman Army was the military of the Romans from the Roman Kingdom in 507 BC to the Roman Republic (507 BC-31 BC) and the Roman Empire (31 BC-395 AD). From the start of the Roman Kingdom in 753 BC to the end of the Byzantine Empire in 1453 AD, it existed for 2,206 years, conserving a core of lasting traditions despite numerous changes in composition, organization, equipment, and tactics. Roman units typically consisted of centuriae (80 men), cohorts (6 centuriae; 480 men), and a legion (10 cohorts; 5,000 men). Any man from ages 16 to 46 were selected by ballot and assigned to legion; the Roman Army typically had 150,000 soldiers at all times, and 3/4 of the rest were levied. A typical Roman army consisted of between five and six legions. Under Augustus, the army grew to 250,000 men, and they peaked at 450,000 in 211 AD, consisting of 33 legions and 400 auxiliary regiments. Under Diocletian, the army was restored to around 400,000 men, but, as the centuries progressed and Rome was invaded by barbarians, large percentages of soldiers in the Roman Army were barbarian mercenaries. This ultimately led to the downfall of the Western Roman Empire at the hands of former mercenary Odoacer in 476 AD, and the Roman Army would become the Byzantine Army.